diff --git a/dvc.lock b/dvc.lock
index 7f8710d..a1378cf 100644
--- a/dvc.lock
+++ b/dvc.lock
@@ -4,21 +4,21 @@ stages:
     cmd: ./gen.py > schema.json
     deps:
     - path: gen.py
-      md5: efb0a465d94a16365e9654a470bd7ef2
-      size: 5597
+      md5: e49f62cdbd3ca8648a29c716ad19f14c
+      size: 5618
     outs:
     - path: schema.json
-      md5: d2e598efee4b54b6460956edb662a9e4
-      size: 11638
+      md5: 6dc7651926e6c6a7c035b26e011d4e72
+      size: 11762
   check_updated:
     cmd: ./gen.py | diff schema.json -
     deps:
     - path: schema.json
-      md5: d2e598efee4b54b6460956edb662a9e4
-      size: 11638
+      md5: 6dc7651926e6c6a7c035b26e011d4e72
+      size: 11762
   tests:
     cmd: pytest -vv tests.py
     deps:
     - path: schema.json
-      md5: d2e598efee4b54b6460956edb662a9e4
-      size: 11638
+      md5: 6dc7651926e6c6a7c035b26e011d4e72
+      size: 11762
diff --git a/examples/valid/params.dvc.yaml b/examples/valid/params.dvc.yaml
index 4bb7bc9..b73cffd 100644
--- a/examples/valid/params.dvc.yaml
+++ b/examples/valid/params.dvc.yaml
@@ -14,3 +14,9 @@ stages:
           - loss
     outs:
       - params2.yaml
+  use-full-params_file:
+    cmd: cat full_file.yaml > params2.yaml
+    params:
+      - my_params.yaml:
+    outs:
+      - params2.yaml
\ No newline at end of file
diff --git a/gen.py b/gen.py
index 2fef035..58bfdb7 100755
--- a/gen.py
+++ b/gen.py
@@ -61,7 +61,7 @@ class CustomParamFileKeys(BaseModel):
 
 
 class Param(BaseModel):
-    __root__: Union[ParamKey, CustomParamFileKeys]
+    __root__: Union[ParamKey, CustomParamFileKeys, Dict[FilePath, None]]
 
 
 class Params(BaseModel):
diff --git a/schema.json b/schema.json
index 0b6d0ab..ae40a88 100644
--- a/schema.json
+++ b/schema.json
@@ -78,6 +78,12 @@
         },
         {
           "$ref": "#/definitions/CustomParamFileKeys"
+        },
+        {
+          "type": "object",
+          "additionalProperties": {
+            "type": "null"
+          }
         }
       ]
     },